Ah, Mars. My favourite of the inner planets, because it is so close (astronomically speaking) but yet it is mostly a mystery to us, and it has such an interesting past. And this is exactly what we are going to talk about today.
Scientists think that once upon a time, a long time ago, Mars was once much like Earth. It had an atmosphere, it had water (in fact, they think the northern hemisphere was mostly covered whilst the southern was mostly land! Imagine a planet where all the northern hemisphere was water and all the southern was land, how cool would that be?) and, like Earth, to this day it still has seasons, weather and everything!
So, what happened?
